Hi all, I've been using ivtv inside of Xen for several months now with great success inside of Xen's main domain (dom0 in Xen parlance). Now I am trying to get ivtv to run inside of a domU, one of the virtual copies of Linux. I've been working with then Xen guys and they have come to this conclusion:
"I think the ivtv driver is probably not calculating dma addresses in the way that xen requires. On native Linux, if you allocate a multi-page chunk of physical memory, you can pass the start address of that buffer to hardware and it can dma the entire buffer given just that address. In Xen, because we give guests 'pseudo-physical' memory, that physical buffer may not be really physically contiguous. So we need drivers to dma_alloc_coherent or pci_alloc_consistent the memory they will use for dma --- we modified those functions to ensure they return suitable contiguous physical memory." Could anyone provide some assistance on this subject? I'm a bit over my head when it comes to kernel coding. You can see the entire conversation at this url: http://lists.xensource.com/archives/html/xen-devel/2005-07/msg00095.html We also found a small bug that exists in 0.2.0 and 0.3.x that causes ivtv to oops when modprobing it inside a Xen domU - in ivtv-driver.c, in the function ivtv_setup_pci (around line 675 in 0.2.0-rc3k) there's this if statement: if (pci_bus != NULL && pci_bus->vendor == PCI_VENDOR_ID_VIA) { .... } else IVTV_KERN_INFO("XXX PCI device: 0x%04x vendor: 0x%04x\n", pci_bus->device, pci_bus->vendor); That else needs to be "else if (pci_bus != NULL)", otherwise it dereferences a NULL and crashes under Xen. With that change it loads properly, but I still have the DMA issue. Any help would be greatly appreciated. I think Xen is going to be huge and being able to use IVTV in it will be useful to a lot of people in the near future. Thanks, Dave -- David Muench - [EMAIL PROTECTED] Jabber ID: [EMAIL PROTECTED] ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_idt77&alloc_id492&op=click _______________________________________________ ivtv-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ivtv-devel
